This invention relates to a chamfer processing method and device, and more particularly to the R-chamfer (synonymous with bevel) process (hereinafter referred to only as chamfer for clarity) to mass-produce specialized components such as the end faces of small metal plate-like parts (hereinafter referred to as plate material) with complicated shapes, including the traverse element for a drive belt for a Continuously Variable Transmission (CVT) (hereinafter only referred to as the traverse element).
Although barrel grinding (also known as barrel polishing) is used in many cases, the chamfer size is small. This type of chamfer is unsuitable for a deeper chamfer required to manufacture the traverse element. Accordingly, in considering the generally known technology to perform chamfer processing of the traverse element, the above-mentioned subject matter remains to be solved. The technology for this function has been previously proposed in Japanese laid-open (Kokai) patent application number (A) Heisei 2-146334 (1990) titled “DRIVING BELT, ELEMENT FOR DRIVING BELT, AND MANUFACTURE THEREOF,” and Japanese laid-open (Kokai) patent application number (A) Heisei 11-77499 (1999) titled “CHAMFERING METHOD OF PLATE MATERIAL, AND CHAMFERING DEVICE.”
The aforementioned technology chamfers the plate material end faces by pivoting (i.e., rocking motion) the plate material while in contact with a grinding belt (also called an abrasive belt). Because of the large pivot radius of the plate material in contact with the grinding belt, only a large curvature radius can be carried out. On the other hand, the traverse element has a specialized shape. The inside slot which forms the neck of the traverse element becomes narrow, which makes deep chamfer processing difficult to accomplish.
In the above-mentioned chamfer method in order to perform a deep chamfer, the grinding belt tension is tightened. Moreover, this method employs variable belt tensions to control the fluctuation in the amount of chamfer processing. As a result, the heavier load on the grinding belt shortens its longevity and wears the belt out quickly. These factors make the equipment more complex to operate, as well as increase running and equipment costs.